KR910001350B1 - Ceramic vessel and method for producing thereof - Google Patents

Abstract

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Description

Airtight ceramic container and manufacturing method thereof

1 (a) -1-1 (b) are diagrams for explaining a conventional method for manufacturing an airtight ceramic container.

2 and 3 are cross-sectional views of a conventional vacuum valve.

4 (a), 4 (b) and 5 (a) to 5 (c) are views showing a solder material thin plate which can be suitably used in the present invention.

6 is a view showing how to use the solder thin plate of FIG.

7 and 8 are cross-sectional views showing an example of a vacuum valve obtained in accordance with an embodiment of the present invention.

9 to 11 are cross-sectional views showing main parts of vacuum valves obtained through other embodiments of the present invention.

* Explanation of symbols for the main parts of the drawings

1: Ceramic Cylindrical Body 1 ', 16: Part

2, 2a, 2b: cover 3a, 3b: contact

4a: fixed terminal 4b: movable terminal

5a: high accuracy all axis 5b: movable degree all axes

6: arc shield 6 ':

7 bellow 11.14 silver solder material

13 spacer 15 stress relief member

31, 33: solder material layer 32: barrier layer

The present invention relates to an air-tight ceramic container, a method of manufacturing the same, and a method of manufacturing a vacuum valve using the airtight ceramic container.

Since ceramic is an insulating material having excellent heat resistance, it can be used as a variety of electrical component materials utilizing its characteristics.

The airtight container used for electrical components, such as a vacuum valve, also belongs to the example.

In the case of such an airtight container, the inside is kept in a vacuum or filled with an inert gas. Therefore, in order to maintain such an internal atmosphere, strict confidentiality must be maintained.

The conventional hermetic ceramic container has a structure in which the open end of the ceramic cylindrical body 1 is sealed with a metal cover 2 as shown in FIG. 1 (a).

In the manufacture of such an airtight ceramic container, a method has been conventionally used in which a metal lid is bonded by brazing after a metalizing treatment is performed on the open end face of the ceramic cylindrical body 1.

In this case, the ceramic cylindrical body 1 and the metal cover 2 have different thermal expansion coefficients, so that thermal stress is generated by heating at the joining portion thereof.

If this thermal stress is large, a crack will arise in the ceramic cylinder 1, and sufficient airtightness will not be obtained. Therefore, in order to lower the thermal stress and prevent the occurrence of cracks, the following study was conducted.

First, as a metal cover, a metal having a small coefficient of thermal expansion such as Mo or W, or an alloy having a small coefficient of thermal expansion such as inver or kovar is used.

Secondly, as shown in Fig. 1 (a), the ends of the metal cover 2 are bent and the end faces are bonded (endface-bonding) to the end faces of the ceramic cylindrical body 1, thereby joining them together. It is to reduce the area.

Since the magnitude of the thermal stress generated at the joint is proportional to the joint area of the two joints, this cross-sectional joint contributes to lowering the thermal stress.

In such cross-sectional joining, in order to obtain sufficient bonding strength and airtightness, as shown in FIG. 1 (b), a solder layer 8 extends from the end of the lid 2 toward the ceramic cylindrical cross section. It is necessary to have a junction structure.

Next, the metallizing method used for manufacture of the said airtight ceramic container is demonstrated. The metallizing method conventionally implemented is as follows.

① Method of metallizing by coating Mo- or W-based powder on the surface of ceramic base material and heating it to 1400-1700 ℃ in reducing atmosphere, for example.

If necessary, a plating treatment such as Ni is performed on the metallizing layer. This method is problematic for cumbersome processes such as requiring treatment at very high temperatures for metallization.

② Method of metalizing by placing Au or Pt on the surface of ceramic base material and heating it under pressure.

In this method, expensive precious metals are used, so a problem arises in economics in a vacuum valve having a large junction area. Furthermore, application of electronic components that are difficult to deform is undesirable because high pressure is required to increase airtightness.

(3) A method of metallizing by heat treatment at a temperature higher than the melting point of these alloys using active metals such as Ti and Zr and transition metals such as Ni and Cu on a ceramic base material (Japanese Patent Laid-Open No. 58-163093).

This method uses Ti and Zr as active metals to form alloys of these active metals with transition metals such as Cu and Ni. In the eutectic composition, the alloys are several hundred degrees Celsius above the melting point of any individual. The lower melting point is used. In this method, since the active metal wets the ceramic base material, it can be metallized with little pressurization.

In addition, there is an advantage that can be metallized with a strong adhesion to the ceramic base material by the effect of the active metal.

In order to manufacture a gas-tight ceramic container by any of the above metallization methods from 1 to 3, the cover must be soldered after metallizing the cross section of the ceramic cylinder.

That is, in order to secure the airtightness of the metallizing process and the container, the soldering of the cover must be performed separately, and the process is complicated. Thus, a method of manufacturing an airtight ceramic container by soldering a metal cover to an opening end surface of a ceramic cylinder without performing the above metallizing has been studied. On the other hand, the following one-step joining method was invented by joining a ceramic member and a metal member without performing metallization (Japanese Patent Laid-Open No. 59-32628).

That is, a bonding method using a low melting point solder material (particularly Ag solder material) containing Ti and / or Zr as the active metal, or laminating an active metal sheet and Ag solder (Ag-solder) It is a joining method which inserts and heats between a member and a metal member.

This one-step joining method can simplify the process since it does not require metallizing.

However, in the case of the one-step joining method, it is not possible to obtain a preferable joining structure as described in FIG. 1 (b). For this reason, when the bonding area of a ceramic member and a metal member is sufficiently large, the joining characteristic which can satisfy | fill substantially can be obtained, but when the joining area is small, sufficient joining characteristic cannot be obtained. Therefore, it is inappropriate to apply to the manufacture of the gas-tight ceramic container described above.

That is, even when soldering using a solder thinfoil 3 larger than the cross section of the lid 2 as shown in FIG. 1 (c), the wettability of the ceramic surface by the molten solder material is not sufficient. As shown in FIG. 1 (d), a solder layer is formed only directly under the cross section of the lid 2.

As a result, gaps tend to occur at the joints and cause a problem that the lid 2 is peeled off even at a minute external pressure.

A conventional vacuum valve using the above airtight ceramic container will be described.

An example of the vacuum valve structure is shown in FIG. In FIG. 2, "1" is a ceramic cylinder. Both lids of the cylindrical body are hermetically bonded to the metal lids 2a and 2b through Ag solder materials 8a and 8b to form a vacuum container in which the inside is kept in vacuum.

In this vacuum vessel, a fixed conductor rod 5a and a movable conduct rod 5b are symmetrical with each other and are installed through the covers 2a and 2b.

As shown in FIG. 2, the high-conduction shaft 5a is fixed to the lid 2a, and the movable conductive shaft 5b is movable in the axial direction. A pair of contacts 3a and 3b are disposed at the end portions of the high-precision shaft and the movable conductive shafts 5a and 5b that face each other. The contact 3a is a fixed contact, and the contact 3b is a movable contact.

The contact 3b is directly soldered to the conductive shaft 5b or soldered to the conductive shaft 5b through an electrode (not shown).

In addition, the end of the high-precision shaft (5a) is a fixed terminal (4a), the other end of the movable conductive shaft (5b) forms a movable terminal (4b). Therefore, the contacts 3a and 3b are opened and closed by the axial movement of the movable conductive shaft 5b.

Bellows 7 are attached to the movable conductive shaft 5b, and the bellows are movable in the axial direction of the movable conductive shaft 5b while keeping the inside of the container in a vacuum-tight manner.

The upper portion of the bellows 7 is provided with a metal arc-shield (not shown) and prevents the bellows 7 from being covered with arc vapor.

In the vacuum vessel, the above-mentioned contacts 3a and 3b are covered to prevent the metal arc shield 6 from being provided and the ceramic cylindrical body 1 being covered with arc vapor.

As a result, the evaporated contact material is attached to the inner surface of the ceramic cylinder 1 to prevent the short circuit. By the way. In the vacuum valve, the arc shield must be fixed to a predetermined position of the vacuum container.

As a result, the convex portion 1 'is formed as shown in the ceramic cylindrical body 1. The convex part 1 'is arranged to bite with the concave part 6' provided in the arc shield 6 and prevents the arc shield 6 from falling off or moving.

The ceramic cylindrical body 1 may have a recessed part, and the arc shield 6 may have a recessed part to bit both. This fixing method has an economical advantage because no metallizing is required for attachment of the ceramic cylindrical body 1 and the arc shield 6.

However, there is an inevitable gap between the two, so that the vibration or movement of the arc shield 6 cannot be avoided when the vacuum valve is subjected to vibration. In addition, there is a drawback of falling off at a predetermined attachment position due to trouble of the recess 6 'of the arc shield 6, resulting in a drop in the breakdown voltage characteristic and the breaking characteristic. The second method of fixing the arc shield 6 to the ceramic cylindrical body 1 is to metallize the inner surface of the ceramic cylindrical body 1, and then solder the arc shield 6 to the inner surface of the ceramic cylindrical body 1. How has been known.

As the metallizing method, the above-described methods of ①-③ are used. According to this method, the falling off or moving trouble of the arc shield 6 can be prevented. However, no matter which method is used in the above ①-③, there is a problem with the above-mentioned metallizing.

That is, the method of (1) has a problem of requiring complicated processes such as high temperature treatment.

In the method of ② not only economic problems. Productivity is also a problem because the apparatus occupies a certain space in the soldering furnace to obtain sufficient pressurization.

In the method of (3), it is difficult to obtain the desired bonding strength.

As a third means for attaching the arc shield 6 to the ceramic cylindrical body 1, the method shown in FIG. 3 is known.

In other words, two ceramic members la and 1b obtained by dividing the cylindrical body in FIG. 3 are prepared, and metallization is performed on the opposite end surfaces 9a and 9b. Then, the flange provided in the arc shield 6a is inserted between the end surfaces 9a and 9b and hermetically sealed. Also in this case, as the metallizing method, the above-described methods of ①-③ are used.

This method also uses a metallizing method, and therefore has the same drawbacks as the second method. In addition, since the metallized portion is increased, it is disadvantageous in terms of economics, and the portion requiring sealing is increased, which is disadvantageous in terms of reliability related to maintaining confidentiality.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and its first object is not to metallize the opening end face of the ceramic cylindrical body in advance, but by providing a periphery of the peripheral portion of the metal cover to the opening end face to achieve a high airtight protection protection function. A hermetic ceramic container can be produced.

A second object of the present invention is to directly fabricate the inner surface of the ceramic cylindrical body and the arc shield in a simple manner and at a sufficient strength, without metallizing the inner surface of the ceramic cylinder when the vacuum valve is manufactured using the airtight ceramic container. It is to provide a method of manufacturing a vacuum valve that can be bonded.

The method of manufacturing an airtight ceramic container according to the present invention comprises the steps of forming an active metal layer by depositing an amount of 0.1-10 mg / cm 2 active metal composed of Ti and / Zr on the open end face of the ceramic cylinder and on the active metal layer. A step of placing a metal solder material on the substrate, a step of arranging a metal cover for sealing the opening of the ceramic cylindrical body so that its peripheral end surface is in contact with the metal solder material, and melting the metal solder material by heating to cover the metal cover material. And soldering to the opening end surface of the ceramic cylindrical body.

The vacuum valve manufacturing method according to the present invention comprises a hermetic ceramic container obtained by the above method and a pair of conductive shafts which are symmetrically disposed to penetrate from the outside to the inside, and which can be opened and closed by moving at least one of them in the axial direction. And a metal contact member provided at the tip of the pair of conductive shafts, a bellow for enabling the movement of the conductive shaft in the axial direction while maintaining the vacuum of the vacuum container, and a metal evaporated from the contact member provided by surrounding the contact member. Process of forming active metal layer by depositing 0.1-10mg / cm2 of active metal powder composed of Ti and / Zr when manufacturing vacuum valve with metal arc shield to prevent adhesion of inner surface of ceramic cylinder And a step of placing a metal solder material on the active metal layer, a step of arranging the arc shield in contact with the metal solder material, and heating. That the molten solder material and a metal having such a step of soldering the shield to the arc inner surfaces of the ceramic cylinder will be characterized.

Detailed descriptions, including explanations of operations required for understanding the present invention, will be given below. First, the joining method which forms the center of this invention is demonstrated.

In the present invention, when joining the ceramic cylindrical body and the metal member, an active metal layer such as Ti or Zr is deposited on the joint surface of the ceramic cylindrical body in advance. This is a simple deposit and differs from the prior art in that it is not particularly metallized.

In other words, the preformed layer is an active metal layer and not a metallization layer. By soldering a metal member on the active metal layer, the active metal reacts with the ceramic cylinder by heating at this time. This leads to metallization and soldering at the same time. This joining method is a one-step joining method in that metallization is not performed in advance.

In particular, in the one step bonding method, the active metal is deposited in a state of being in close contact with the ceramic surface and the deposition amount thereof is limited to 0.1-10 mg / cm 2. Therefore, it differs from the conventional example which used the active metal plate simply on the surface of the ceramic member.

By such a feature, a preferable junction structure as described in FIG. 1B can be obtained.

The reason is that the surface of the ceramic member is well metalized by depositing the active metal and the deposition amount in the above range.

For example, after the active metal powder is coated on the surface of the alumina ceramic disc, 72% Ag-Cu and Ag solder materials are placed and heated in a vacuum state to investigate the diffusion of the solder material. When 10 mg / cm <2> was settled, it was confirmed that a soldering material spread | dispersed moderately and can perform favorable metallization.

As a result of good metallizing as described above, even when the bonding area is small, such as end face bonding, sufficient bonding strength can be achieved and good bonding without gaps can be achieved.

On the other hand, if the deposition amount of the active metal powder is too small or too large, good metallization cannot be performed at the time of soldering, and diffusion of the solder material is worsened. Therefore, no joint with desired characteristics can be obtained.

By applying the above joining method, in the present invention, a highly reliable airtight ceramic container excellent in airtightness can be obtained without increasing the joining time between the ceramic cylindrical body and the metal lid.

By applying the joining method to the joining of the arc shield and the inner surface of the ceramic cylindrical body, it is possible to fix the arc shield without fear of falling off in a simple manner.

In the said joining method, the following method is mentioned as a method for depositing an active metal powder on the joining surface of a ceramic cylinder.

The first method is a method in which an organic adhesive, in which a binder and a solvent are mixed, is applied in advance to a joint surface of a ceramic cylindrical body, and sprayed and attached to the adhesive layer a cyclic metal powder.

The binder and the solvent to be used are not particularly limited, but are preferably completely decomposed and removed in the heat treatment process.

For example, polyvinyl alcohol, ethyl cellulose, etc. are mentioned as a binder, and ethanol tetralin etc. are mentioned as a solvent.

The second method is a method of preparing a mixture of a powder of an active metal, an organic binder and a solvent, and applying the mixture to a joint surface of a ceramic cylinder through a screen made of a metal mash. As the binder and the solvent, those mentioned above are used.

The third method is a method in which a joining surface of a ceramic cylinder deposits an active metal by vapor deposition, sputtering, or the like. In the case of using the coating method or the spraying method among the deposition methods, if the particles are too large, the fluidity is lowered, so it is preferable to set it to 0.1-10 탆. In addition, when using the mixture of Ti and Zr as an active metal, the mixing ratio is not specifically limited, It can set arbitrarily.

On the other hand, it is preferable that the surface roughness of the ceramic cylinder to which the active metal powder is to be deposited is 0.1-10 탆. Too large a surface roughness may result in insufficient bonding strength. As a metal solder material used by the joining method, Ag solder material, such as Ag-Cu system, Ag-Cu-Sn system, Ag-Cu-Zn system, is preferable, for example.

At the time of soldering, a solder material is disposed on the joint surface of the ceramic cylinder on which the active metal powder is deposited, and the metal member (metal cover or arc shield) to be joined is brought into contact with the solder material and heated to a temperature higher than the melting point of the solder material. The heat treatment atmosphere at this time is preferably a non-oxidizing atmosphere such as vacuum or argon gas.

Next, the manufacturing method of the airtight ceramyl container which concerns on this invention is demonstrated. In this case, the material of the ceramic cylindrical body 1 is not specifically limited.

For example, the nitride-based ceramics such as Al ₂ O ₃ such as an oxide-based ceramic, A1N and Si ₃ N ₄ can be used.

As the metal cover 2, it is preferable to use a material whose thermal expansion coefficient is close to that of the ceramic cylinder. This is because the thermal stress at the time of joining can be reduced as mentioned above. Preferable materials include Mo, W Koba, Invar, and the like.

In addition, in order to reduce the bonding area to be bonded to the ceramic cylindrical body 1 and the metal cover 2 to reduce the thermal stress, cross-sectional bonding is used as shown in FIG.

As described above, in the present invention, sufficient bonding strength and airtightness can be obtained even in cross-sectional joining.

By the way, in manufacture of the airtight ceramic container by this invention, when soldering with the ceramic cylindrical body 1 and a metal cover, it is preferable to use the thin solder material plate shown in FIG. 4A or 4B.

As shown in the figure, these solder thin sheets have rough surfaces with irregularities only on the top and smooth surfaces on the bottom. In the thin solder material sheet of FIG. 4B, a hole penetrating the concave portion is drilled.

When the solder material is attached by using the thin solder material plate, the smooth lower surface is brought into contact with the joint surface of the ceramic cylindrical body 1, and the upper surface with the fin is brought into contact with the end face of the metal cover 2. By soldering in this state, the following effects can be obtained.

At the time of soldering, decomposition gas of the impurity gas, adsorption gas, etc. are discharged | emitted from the ceramic cylinder 2 to the inside of the container by the heating. Therefore, in order to achieve a desired atmosphere such as a vacuum in the container, these gases must be discharged to the outside while the soldering is completed.

When the said solder material thin plate is used, the space | interval by 이 arises between the metal cover of the solder material thin plate. Therefore, the above gas is discharged to the outside through this interval to obtain a preferable atmosphere in the container such as a vacuum.

That is, the gas discharge path is secured by the upper surface 凹凸 of the solder material sheet. This effect is further increased by installation of the through holes as shown in FIG. 4B.

However, this discharge path should be completely closed and sealed enough when the sealing is completed by the upper surface of the solder.

Not only such a viewpoint, but also the viewpoint of stability at the time of arrange | positioning a thin solder material plate in a junction part, 20 micrometers-5 mm are suitable for depth or height.

By thinning the lower surface of the solder material sheet, excellent bonding can be obtained even on a ceramic cross section where the wettability to the molten solder material is weak.

If there is a gap between the thin plate of solder material and the surface of the ceramic cylindrical body, the molten solder material cannot be sufficiently diffused on the joint surface which is weak in wettability, and thus excellent bonding cannot be obtained and cause leakage failure.

As described above, the thin solder material plates of FIGS. 4A and 4B form a fin on the upper surface in contact with the metal to secure a gas discharge path, and smooth the lower surface in contact with the ceramic to secure excellent bonding.

5A shows another example of a preferred solder material tube. As shown in the figure, this solder material thin film has a lamination structure between two solder material layers 31 and 32 with a barrier layer made of a metal having a higher melting point than that of the solder material. The two solder material layers 31 and 32 may be the same or different. The effects and actions that can be obtained by using such a solder material thin plate are as follows.

Different types of joining techniques using solder materials, unlike diffusion bonding or fusion welding, do not react the materials to be joined and form an alloy layer. Therefore, it has the advantage of not causing a decrease in strength due to the formation of a weak alloy layer.

However, depending on the type of material to be joined, the components of these members may rapidly diffuse in the fusion solder material and react with each other to form a weak alloy layer. Therefore, in the solder material thin plate of FIG. 5A, by providing the barrier layer 32, the elements which are eluted and diffused in the molten solder material are prevented from contacting each other and the formation of a weak alloy layer is prevented.

That is, since the barrier layer 32 has a high melting point, it remains without melting even when the solder material layers 31 and 33 melt. Therefore, contact between the elements diffused from the welded members on both sides is prevented. The thickness of the barrier layer 32 is not specifically limited. However, the range which acts as a barrier surely and is easy to handle is about 0.01-5 mm.

You may use a thin solder material plate with the structure which combined the structure of FIG. 5A, the structure of FIG. 4A, and FIG. 4B. An example of such a solder material thin plate is shown in FIG. 5B and FIG. 5C. In this case, the gas discharge described in FIGS. 4A and 4B can be simultaneously performed.

FIG. 6 shows a state of manufacturing the airtight ceramic container according to the present invention using the thin solder material plate of FIG. 5C. The other effects other than the above which can be obtained by using the solder material thin plate of FIG. 6 and FIG. 5A-FIG. 5C can be understood.

The barrier layer 32 does not melt even by heating of the solder material attachment and maintains mechanical strength. Therefore, even if the metal cover 2 is slightly misaligned, the barrier layer 32 functions as a connection material, and a desired airtight container can be obtained.

In the manufacturing method of the vacuum valve according to the present invention, when manufacturing the vacuum valve described in FIG. 2, the arc shield is directly bonded to the inner surface of the ceramic cylindrical body 1 using the above-described joining method. Therefore, even in this case, excellent bonding with sufficient strength can be obtained, and dropping and movement of the arc shield can be prevented, thereby improving reliability such as suppressing fluctuations in the breakdown voltage characteristic.

In addition, since the metallizing treatment is not required in advance, the process can be simplified.

Also in manufacture of this vacuum valve, the above-mentioned effect can be acquired by using the solder material thin plate shown in FIG. 5A.

Since the surface roughness of the inner surface of the arc shield has an important effect on the withstand voltage characteristic, it is preferable to set it to 0.1-l0 탆 so as not to lower the withstand voltage characteristic.

The present invention will be described in more detail with reference to the following examples.

Example 1

(Manufacture of Airtight Ceramic Container)

The airtight ceramic container shown in FIG. 1 was manufactured as follows.

An Al ₂ O ₃ ceramic cylindrical body 1 having an outer diameter of 60 mm, an inner diameter of 50 mm, and a height of 60 mm was prepared.

Further, Ti powder and Zr powder having a particle diameter of 5 µm or less were mixed at a ratio of 9: 1, and this was mixed with an ethanol solution of ethyl cellulose to prepare an active metal paste.

Subsequently, this paste was applied to the open end faces of both ends of the ceramic cylindrical body 1. At this time, the coating amount of the paste was adjusted so that the deposition amount of the active metal was 1 mg / cm 2.

Ag solder material (72% Ag-Cu) having a thickness of 50 µm was disposed on the paste coated surface of the ceramic cylinder 1. A metal cover 2 composed of Koba (Ni-Co-Fe alloy) was disposed on the solder material as described in FIG.

The laminated body obtained in this way like FIG. 4 was heated at 850 degreeC for 5 minutes in the vacuum furnace (2x10 <^-5> Torr), and the metallic cover 2 was bonded to the opening end surface of the ceramic cylinder.

After cooling the airtight ceramic container thus obtained, it was taken out of the furnace and the state of the joint was investigated.

As a result, the solder material layer 8 joining the metal cover 2 and the ceramic cylindrical body is diffused toward the metallized ceramic surface, and is firmly fixed by the excellent bonding structure shown in FIG.

When the airtightness of the joint was evaluated by the helium (He) gas leak test on the airtight ceramic container, the amount of He gas leak was 10 ^-10 Torr, 1 / sec or less, and no leakage occurred.

Example 2

(Manufacture of Airtight Ceramic Container)

As shown in FIG. 4A, a donut-shaped thin Ag solder material plate (72% Ag-Cu) having a 의 of 50 µm in height and having an outer diameter of 50 mm, an inner diameter of 40 mm and a thickness of 100 µm was prepared.

An Al ₂ O ₃ ceramic cylindrical body having an outer diameter of 50 mm, an inner diameter of 40 mm, and a height of 60 mm was prepared. Ti powder as much as 1 mg / cm 2 was applied to the open end face of both ends of the ceramic cylindrical body 1. The Ag solder material thin plate was arrange | positioned at this Ti coating surface.

As in Example 1, the metal cover 2 made of Ni-Fe alloy was placed on a thin sheet of solder material and heated for 6 minutes at 880 ° C. in a vacuum furnace (2 × 10 ^-5 Torr) to heat the metal cover 2 in a ceramic cylinder. It joined to the opening end surface of a sieve.

The airtight ceramic container thus obtained was cooled and then removed from the vacuum furnace and examined, and the internal vacuum degree was high and the bonding state was good.

Example 3

(Manufacture of Airtight Ceramic Container)

As shown in FIG. 4B, a donut-shaped thin Ag solder material plate (72% Ag-Cu) having an outer diameter of 40 mm, an inner diameter of 30 mm, and a thickness of 100 μm was prepared, having through holes provided in the concave portion and the concave portion having a height of 100 μm on the surface. .

In addition, an Al ₂ O ₃ ceramic cylindrical body 1 having an outer diameter of 40 mm, an inner diameter of 30 mm, and a height of 40 mm was prepared.

Ti powder of 1 µm / cm 2 was applied to the open end surface of both ends of the ceramic cylindrical body 1. The Ag solder material thin plate was arrange | positioned at this Ti coating surface.

In the same manner as in Example 1, the metal cover 2 made of Ni-Fe alloy was placed on a thin plate of solder material and heated for 6 minutes at 850 ° C. in a vacuum furnace (2 × 10 ^-5 Torr) to ceramic It joined to the opening end surface of a cylindrical body.

The airtight ceramic container thus obtained was taken out of the vacuum furnace after cooling and irradiated, and as a result, the degree of vacuum was high and the bonding state was excellent.

Example 4

In Example 4 and Example 5, the effect of the barrier layer 32 in the thin solder material plate of FIG. 5A was investigated.

As shown in FIG. 5A, between the 50-micrometer-thick Ag solder material layer 31 composed of 4% Ti-69% Ag-Cu and the 50-micron-thick Ag solder material layer 33 composed of 72% Ag-Cu, 13% Cr- A thin solder material plate provided with a barrier layer 32 having a thickness of 50 μm made of Fe was produced.

An Al ₂ O ₃ ceramic cylindrical body 1 having an outer diameter of 40 mm, an inner diameter of 30 mm, and a height of 60 mm was prepared.

A thin solder material plate was disposed on the open end face of the ceramic cylindrical body 1.

The metal cover (2) made of Ni-Fe alloy with Ni plating on the surface was placed on a thin plate of solder material and placed in a vacuum furnace (2 × 10 ^-5 Torr) and heated at 850 ° C. for 10 minutes to prepare the metal cover (2) in ceramic. It joined to the opening end surface of a cylindrical body.

The airtight ceramic container thus obtained was cooled and then taken out of a vacuum furnace and examined to obtain excellent bonding over the entire bonding surface.

For comparison, a 100 μm thick solder material plate composed of 1% Ti-71% Ag-Cu was used, except that bonding experiments were conducted under the same conditions as described above.

As a result, there was a partial defect in bonding. This poor bonding is considered that Ni diffused from the Ni plating layer of the metal cover 2 formed an alloy with Ti in the solder material.

Example 5

4C Ti-69% Ag-Cu solder material layer 31 having a thickness of 40㎛, Mo barrier layer 32 having a thickness of 20㎛, as shown in FIG. The Ag-Cu solder material layer 33 which formed the convex part was layered sequentially, and the solder material thin plate was produced.

An Al ₂ O ₃ ceramic cylindrical body 1 having an outer diameter of 50 mm, an inner diameter of 40 mm, and a height of 60 mm and a metallic lid 2 made of 42% Fe-Ni were prepared.

Subsequently, as shown in FIG. 6, the ceramic cylindrical body 1, the thin plate of solder material and the metal cover 2 were placed and placed in a vacuum furnace (2 × 10 ^-5 Torr) and heated at 850 ° C. for 10 minutes to thereby heat the ceramic cover 2. It joined to the cylindrical opening end surface.

The airtight ceramic container obtained in this way was taken out of the vacuum furnace, and examined. As a result, although the position of the metal lid 2 was slightly shifted, the continuous agent was retained by the barrier layer 32 and the airtightness was also excellent.

Example 6-8

(Manufacture of Vacuum Valve)

The vacuum valve shown in FIG. 7 and FIG. 8 was manufactured. In the drawings, the same reference numerals are given to the same parts as those in FIGS. 2 and 3.

Outer diameter 123 mm, inner diameter 110 mm. An Al ₂ O ₃ ceramic cylindrical body 1 having a height of 170 mm was prepared, and the inner surface 21 thereof was polished.

The degree of polishing was adjusted to have surface roughnesses of 0.1 탆 (Example 6), 0.5 탆 (Example 7), and 10 탆 (Example 8).

Subsequently, a Ti powder having an average particle diameter of 3.5 µm was prepared, and the Ti powder was uniformly applied to the required portion (part to which the arc shield 6 was to be bonded) on the inner surface of the ceramic cylindrical body polished with the active metal coating layer 12 Formed).

The coating amount was 1 mg / cm 2 and the coating method was applied through a metal mash. However, after masking other than necessary parts, you may use the method of adhering by sputtering, vacuum deposition, or ion plating.

As shown in FIG. 8, a silver solder material having a thickness of 0.2 mm was inserted and soldered between the Ti coated surface 21 and the concave portion 10 provided on the (sustained) arshield 8.

This raw material adhesion was performed for 6 minutes at a vacuum degree (2 × 10 ^-5 Torr) and a temperature of 850 ° C. As a result, in any of Examples 6, 7, and 8, the arc shield was completely connected without a shape.

The in-pulse withstand voltage test by the elevating method was performed about the vacuum valve obtained in the said Example 6-8.

As a result, as shown in FIG. 2, when the in-pulse withstand voltage of the conventional vacuum valve was 100%, all high values of 130% were obtained.

The result is that the concave portion 10 is not provided on the inner surface of the ceramic cylinder. This is due to the synergistic effect of achieving complete confidentiality.

Example 9

(Manufacture of vacuum valve)

A junction structure was formed between the arc shield 6 and the ceramic cylindrical body 1 as shown in FIG. In this case, the arc shield 6 is not provided with the concave portion 10 of FIG. Instead, a sus spacer 13 and a silver solder material 14 were inserted between the junction of the sus arc shield 6 and the inner surface 21 of the ceramic cylinder.

By the polishing treatment, the surface roughness of the inner surface of the ceramic cylindrical body 21 was 0.5 μm. In addition, the active metal layer 12 was formed by attaching Ti powder having an average particle size of 3.5 μm as an active metal powder by 1 mg / cm 2 to the joining scheduled portion as in Examples 4 to 6.

They were melted under the conditions of vacuum (2 × 10 ^-5 Torr) and a temperature of 850 ° C. for 6 minutes to melt the silver solder materials 11 and 14 to insert the active metal powder into the inner surface 21 of the ceramic cylinder 1. Joining was performed.

As a result, the shock load of 150 kgf was repeated 100,000 times with respect to the resultant vacuum valve, but there was no movement or abnormality of the arc shield.

As a result of the withstand voltage test by the inpulse withstand voltage test (elevation method), a value of 140% was obtained by setting the inpulse withstand voltage value of the conventional vacuum valve of FIG.

[Examples 10 and 11]

(Manufacture of vacuum valve)

A stress relief mechanism was provided at the joining of the ceramic cylindrical body 1 and the arc shield 6.

That is, in Example 10, the stress relaxation member 15 was inserted between the ceramic cylinder 1 and the arc shield 6. In Example 11, the recessed part 16 was provided in a part of the arc shield 6, and the stressed part 16 was made to stress relief.

Since the thermal expansion coefficient is about one digit different in the ceramic cylinder 1 and the arc shield 6, heat distortion may occur in the arc shield depending on the heating method and conditions in the solder material. Therefore, the thermal stress is alleviated by the structure of FIG. 10 or 11 degrees.

Except for adopting the stress relaxation mechanism, the arc shields were bonded under the same conditions as in Example 6-8 to manufacture vacuum valves.

When the same in-pulse withstand voltage test was carried out on the resultant vacuum valve, the values of l35% in Example 10 and 140% in Example 11 were obtained.

There was no distortion of the arc shield in any vacuum valve.

[Examples 12 and 13]

(Manufacture of vacuum valve)

In Example 6-11, the active metal powder of 3.5 micrometers in average particle diameter is used. The effect was investigated by changing the particle size of the active metal. In other words, the active metal powders having an average particle diameter of 1 µm (Example 12) and 10 µm (Example 13) were used in the same manner as in Example 9 except for the above.

As a result, in any case where the average particle diameter was 1 μm (Example 12) and 10 μm (Example 13), the same excellent bonding state as in Example 7 (3.5 μm) was obtained.

[Examples 14 and 15], [Comparative Examples 1 and 2]

(Manufacture of vacuum valve)

To investigate the effect of the coating amount of the active metal powder, the coating amount was 0.01 mg / cm 2 (Comparative Example 1), 0.1 mg / cm 2 (Example 14), 10 mg / cm 2 (Example 15), 50 mg / cm 2 (comparative). Example 2) was carried out and the same procedure as in Example 9 was performed except for the above.

As a result, in Comparative Example 1 (0.01 mg / cm 2), the bonding state between the arc shield and the ceramic member was not sufficient and the movement of the shield could be seen when the impact was applied.

In addition, the variation in the breakdown voltage also occurred in the in-pulse withstand voltage test. Also in Comparative Example 2 (50 mg / cm 2), bonding was insufficient and good bonding could not be obtained.

As a result, the deviation was also confirmed in the in-pulse withstand voltage value.

On the contrary, in Examples 14 and 15 (0,1 mg / cm 2 and 10 mg / cm 2), there was no movement of the arc shield and no change in the impulse withstand voltage value.

Example 16

In this example, a mixed powder of Ti: Zr = 1: 1 was used as the active metal powder, except that all were carried out in the same manner as in Example 9.

As a result, there was no movement of the arc shield and the inductance withstand voltage characteristic was good at 130%.

As described above, according to the present invention, an airtight ceramic container having sufficient bonding strength and high airtightness retention function can be manufactured by cross-sectional joining the peripheral portion of the metallic cover to the opening end face without metalizing the opening end face of the ceramic cylinder in advance. have.

It is used as a convenient method when manufacturing the vacuum valve in which the arc shield is fixed inside the hermetic ceramic container, and it is possible to manufacture the vacuum valve in which the arc shield is bonded with sufficient strength and the voltage resistance is stabilized.

Claims (8)

Depositing an active metal composed of Ti and / Zr in an amount of 0.1-10 mg / cm 2 on the ceramic cylindrical opening end surface, forming an active metal layer, placing a metal solder material on the active metal layer, and ceramic Arranging a metal cover for sealing the opening of the cylindrical body in contact with the metal solder material on its periphery end face; melting the metal solder material by heating and soldering the metal cover to the opening end surface of the ceramic cylinder. A method for producing an airtight ceramic container, characterized in that. The method of manufacturing an airtight ceramic container according to claim 1, wherein a method of applying a paste containing a powder of the active metal is used to deposit the active metal. The method of manufacturing a gas-tight ceramic container according to claim 1, wherein a method of dispersing and attaching the active metal powder to an opening end surface of the ceramic cylinder coated with an adhesive to deposit the active metal is used. The method for manufacturing an airtight ceramic container according to claim 2 or 3, wherein the active metal powder has an average particle diameter of 10 µm or less. The method of manufacturing a gas-tight ceramic container according to claim 1, wherein the upper surface is provided with a metal solder material along the width direction of the open end surface of the ceramic container, and the lower surface is a thin metal solder material thin plate. The method of manufacturing a gas-tight ceramic container according to claim 5, wherein as the metal solder material, a metal solder material tube provided with a through hole along the width direction of the open end solder material of the ceramic container is used. The thin metal solder material thin plate according to any one of claims 5 and 6, wherein a barrier layer made of a metal having a higher melting point than these metal solder materials is inserted between two metal solder materials as the metal solder material. A method for producing an airtight ceramic container, characterized in that it is used. A hermetic ceramic container made by the method according to any one of claims 1, 2, 3, 5 and 6.

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